In article <kj9ge6$272$1@news.albasani.net>, IV <ivgroups@onlinehome.de> wrote:>>It seems that computer algebra systems like Maple (version 11) and >Mathematica (version 7) can not solve all simply solvable equation systems >automatically. Let us look e.g. at the equation system [c1=A*B/C, c2=C*A/D, >D=c3-A, C=A-B], where c1, c2 and c3 are real or complex constants, A, B, C >and D are real or complex variables, and the solutions for the variable A >are wanted. The equation system forms a cubic equation in A, and the >solutions of the equation system are the solutions of this cubic equation. >But the solve command can find neither the cubic equation nor its solutions. >I think, the equation system has to be somehow prepared to yield a normal >form of equation systems. Is a normal form for polynomial equation systems >known?

As Axel Vogt has pointed out, solving this system is straightforwardin Maple, and I suspect in Mathematica as well. Probably you did notenter the commands correctly.

Axel presented his solution in Maple 17. Since you mentioned Maple 11,I tested the same on Maple 11. Works fine.